content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  package io.reactivex.observable;
  
  import io.reactivex.common.annotations.NonNull;
  
  /**
   * A functional interface that has a {@code subscribe()} method that receives
   * an instance of a {@link SingleEmitter} instance that allows pushing
   * an event in a cancellation-safe manner.
   *
   * @param <T> the value type pushed
   */
  public interface SingleOnSubscribe<T> {
  
      /**
       * Called for each SingleObserver that subscribes.
       * @param e the safe emitter instance, never null
       * @throws Exception on error
       */
      void subscribe(@NonNull SingleEmitter<T> e) throws Exception;
  }
  
  